diff --git a/lib/bcoin/bloom.js b/lib/bcoin/bloom.js
index b93eef89..7d3c6912 100644
--- a/lib/bcoin/bloom.js
+++ b/lib/bcoin/bloom.js
@@ -360,10 +360,6 @@ RollingFilter.prototype.added = function added(val, enc) {
   return false;
 };
 
-/*
- * Murmur3
- */
-
 /**
  * Murmur3 hash.
  * @memberof Bloom
diff --git a/lib/bcoin/merkleblock.js b/lib/bcoin/merkleblock.js
index bedadc29..38cac67e 100644
--- a/lib/bcoin/merkleblock.js
+++ b/lib/bcoin/merkleblock.js
@@ -30,8 +30,8 @@ var constants = bcoin.protocol.constants;
  * @property {Buffer[]} hashes
  * @property {Buffer} flags
  * @property {TX[]} txs - Transaction vector.
- * @property {Hash[]} tx - List of matched tx hashes.
- * @property {Object} txMap - Map of matched tx hashes.
+ * @property {Hash[]} matches - List of matched tx hashes.
+ * @property {Object} map - Map of matched tx hashes.
  * @property {ReversedHash} rhash - Reversed block hash (uint256le).
  */
 
@@ -50,8 +50,8 @@ function MerkleBlock(data) {
   this.flags = data.flags || [];
 
   // List of matched TXs
-  this.txMap = {};
-  this.tx = [];
+  this.map = {};
+  this.matches = [];
   this._validPartial = null;
 
   // TXs that will be pushed on
@@ -100,12 +100,17 @@ MerkleBlock.prototype.getRaw = function getRaw() {
  */
 
 MerkleBlock.prototype.addTX = function addTX(tx) {
+  var index, hash;
+
   if (!(tx instanceof bcoin.tx))
     tx = new bcoin.tx(tx);
 
+  hash = tx.hash('hex');
+  index = this.map[hash];
+
   this.txs.push(tx);
 
-  tx.setBlock(this, -1);
+  tx.setBlock(this, index);
 
   return tx;
 };
@@ -122,12 +127,12 @@ MerkleBlock.prototype.hasTX = function hasTX(hash) {
 
   this.verifyPartial();
 
-  return this.txMap[hash] === true;
+  return this.map[hash] != null;
 };
 
 /**
  * Verify the partial merkletree. Push leaves onto
- * {@link MerkleBlock#tx} and into {@link MerkleBlock#txMap}.
+ * {@link MerkleBlock#tx} and into {@link MerkleBlock#map}.
  * @private
  * @returns {Boolean}
  */
@@ -145,8 +150,8 @@ MerkleBlock.prototype.verifyPartial = function verifyPartial() {
     return false;
   }
 
-  this.tx = tree.matches;
-  this.txMap = utils.toMap(tree.matches);
+  this.matches = tree.matches;
+  this.map = tree.map;
   this._validPartial = true;
 
   return true;
@@ -167,6 +172,7 @@ MerkleBlock.prototype.extractTree = function extractTree() {
   var hashUsed = 0;
   var matches = [];
   var indexes = [];
+  var map = {};
   var failed = false;
   var bits = new Array(flags.length * 8);
   var totalTX = this.totalTX;
@@ -179,7 +185,7 @@ MerkleBlock.prototype.extractTree = function extractTree() {
   }
 
   function traverse(height, pos) {
-    var parent, hash, left, right;
+    var parent, hash, left, right, txid;
 
     if (bitsUsed >= bits.length) {
       failed = true;
@@ -195,8 +201,10 @@ MerkleBlock.prototype.extractTree = function extractTree() {
       }
       hash = hashes[hashUsed++];
       if (height === 0 && parent) {
-        matches.push(hash.toString('hex'));
+        txid = hash.toString('hex');
+        matches.push(txid);
         indexes.push(pos);
+        map[txid] = pos;
       }
       return hash;
     }
@@ -219,7 +227,7 @@ MerkleBlock.prototype.extractTree = function extractTree() {
   if (totalTX == 0)
     return;
 
-  if (totalTX > (constants.block.MAX_SIZE / 60 | 0))
+  if (totalTX > constants.block.MAX_SIZE / 60)
     return;
 
   if (hashes.length > totalTX)
@@ -246,7 +254,8 @@ MerkleBlock.prototype.extractTree = function extractTree() {
   return {
     root: root.toString('hex'),
     matches: matches,
-    indexes: indexes
+    indexes: indexes,
+    map: map
   };
 };
 
@@ -306,7 +315,7 @@ MerkleBlock.prototype.inspect = function inspect() {
     hashes: this.hashes.map(function(hash) {
       return hash.toString('hex');
     }),
-    tx: this.tx,
+    map: this.map,
     flags: this.flags
   };
 };
diff --git a/test/block-test.js b/test/block-test.js
index d39690ae..d7981cd0 100644
--- a/test/block-test.js
+++ b/test/block-test.js
@@ -51,16 +51,16 @@ describe('Block', function() {
 
   it('should parse partial merkle tree', function() {
     assert(mblock.verify());
-    assert.equal(mblock.tx.length, 2);
+    assert.equal(mblock.matches.length, 2);
     assert.equal(mblock.hash('hex'),
       '8cc72c02a958de5a8b35a23bb7e3bced8bf840cc0a4e1c820000000000000000');
     assert.equal(mblock.rhash,
       '0000000000000000821c4e0acc40f88bedbce3b73ba2358b5ade58a9022cc78c');
     assert.equal(
-      mblock.tx[0],
+      mblock.matches[0],
       '7393f84cd04ca8931975c66282ebf1847c78d8de6c2578d4f9bae23bc6f30857');
     assert.equal(
-      mblock.tx[1],
+      mblock.matches[1],
       'ec8c51de3170301430ec56f6703533d9ea5b05c6fa7068954bcb90eed8c2ee5c');
   });
 
diff --git a/test/tx-test.js b/test/tx-test.js
index 834fe809..38ad5a16 100644
--- a/test/tx-test.js
+++ b/test/tx-test.js
@@ -631,5 +631,12 @@ describe('TX', function() {
     assert.equal(wtx.getSize(), 62138);
     assert.equal(wtx.getVirtualSize(), 61813);
     assert.equal(wtx.getCost(), 247250);
+    var raw1 = wtx.render();
+    clearCache(wtx, true);
+    var raw2 = wtx.render();
+    assert.deepEqual(raw1, raw2);
+    var wtx2 = bcoin.tx.fromRaw(raw2);
+    assert.equal(wtx.hash('hex'), wtx2.hash('hex'));
+    assert.equal(wtx.witnessHash('hex'), wtx2.witnessHash('hex'));
   });
 });